Pyrolyzed vapors from “material” (“material” can consist of and/or contain petroleum compounds, plastics, tires, biomass (both vegetal and animal), solid wastes, extracts of liquid wastes, or a combination thereof) can, when condensed completely, produce a liquid known as bio-oil. The resulting raw bio-oil includes a high proportion of water and organic acids, and other thermal decomposition products from the pyrolized material. Raw bio-oil is often chemically unstable and typically rapidly polymerizes. Moreover the energy content or energy density of raw bio-oil is about half that of crude oil, due mostly from the amount of water and polar species contained within. Raw bio-oil is generally also very acidic and corrosive to some parts found in standard motors and turbines. Raw bio-oil often cannot be blended directly with other petroleum fuels due to its polarity as well as water content. Upgrading and de-watering raw bio-oil has, to this point, been difficult and expensive, making conventionally produced bio-oil economically unattractive.
One method for processing bio-oil vapors obtained from a slow pyrolysis process involves quenching the vapors with biodiesel in a single-pass or stage. While this method may operate acceptably for some situations, continually feeding pure biodiesel into a quenching vessel to condense the bio-oil may prove costly for long-duration processes. Further, significant volumes of biodiesel may prove impractical to employ for such a system. In addition, a slow pyrolysis technique often produces lower quantity bio-oil, therefore negatively affecting the economics of such a system. Moreover, resulting bio-oil/biodiesel fuel mixtures produced with bio-oil extracted via the single-pass process may have problems passing fuel combustion standards, such as ASTM D975 or D6751.
What is needed is a more economical and practical system and method to extract bio-oil components from pyrolyzed material.